import cv2
import numpy as np

fire = cv2.imread('bilibili.png')
kernel = np.ones((10,10),np.uint8)
erosion_1 = cv2.erode(fire,kernel,iterations = 1)
erosion_2 = cv2.erode(fire,kernel,iterations = 2)
erosion_3 = cv2.erode(fire,kernel,iterations = 3)
res = np.hstack((erosion_1,erosion_2,erosion_3))
cv2.imshow('res',res)
cv2.waitKey(0)
cv2.destroyAllWindows()